Participation of a broad variety of actors in decision-making processes has become an important issue in science and technology policy. Many authors claim the involvement of stakeholders and of the general public to be a core condition for legitimate and sustainable decision making. In the last decades, a wide spectrum of procedures has been developed to realize biotechnological citizenship. These procedures, composed of multiactor arenas, are either located in close relation to the system of politics, or, as in the case of administrative decision making, more closely to the system of law. In the latter case, a problematic constellation arises. Here, law and science can build a techno-scientific normativity that systematically excludes political discourse. The law, although intending to provide for political freedom and citizenship rights, at the end appears to be an "iron cage" for political communication.